Some of the internet that Ryoutarou has appeared in are as follows.

2005.??.??	Norikonde Koi-Koi-Koi 58 [radio]	guest
2017.09.24	TGS2017 Shin Tennis no Oujisama Rising Beat stage	guest
2023.09.29	Ikenai Kyou Housou Chokuzen Tokuban	guest